Because nucleic acid detection can accurately predict and estimate the infectivity and results of the virus, it is now used as an evaluation result in the screening of many people in China. However, with the increasingly severe situation of prevention and control, antigen detection can also be used as an auxiliary detection means. Although the accuracy of antigen detection is not high, it has a very good performance and function in the primary screening of large-scale people.
One: nucleic acid detection is more effective because of higher requirements for equipment and collectors.
Nucleic acid detection is one of the important criteria for the diagnosis of COVID-19 because of its outstanding characteristics of early diagnosis, high sensitivity and specificity. Real-time fluorescence quantitative RT-PCR was used for nucleic acid detection. This technology is very useful, which is helpful for COVID-19's initial discovery and judgment. However, the disadvantage is that the high-sensitivity RT-PCR instrument is expensive, which requires high cleanliness and operators of related laboratories and takes a long time to detect. A test usually takes 4-6 hours to get the results.
Two: antigen detection has faster preliminary test results than nucleic acid detection, but the disadvantage is low accuracy.
Antigen detection can quickly detect whether a human sample contains novel coronavirus based on the detection results, and has low requirements for equipment and personnel. The double antibody sandwich method used in antigen detection will use two antigen-specific antibodies to recognize and bind different epitopes of an antigen target, which can reduce the probability of cross-reaction and effectively improve its specificity. In this way, the test results can be obtained quickly.
Three: antigen detection is only suitable for large-scale basic diagnosis of many people, and the final diagnosis still depends on nucleic acid detection.
In daily life, because the detection time of nucleic acid detection is not short, when large-scale people carry out related detection, there may be the risk of aggregated infection. At this time, rapid crowd screening and preliminary structural diagnosis of the virus can be carried out through antigen detection. This is very helpful for reducing the pressure of prevention and control and ensuring the diversion of personnel.